Low-voltage power circuit breakers have contact arrangements in order to make it possible to rapidly connect or isolate the circuit breaker to or from current-carrying rails. This is desirable, inter alia, for the purpose of removing or carrying out maintenance on the low-voltage power circuit breakers. Low-voltage power circuit breakers are provided with different sizes for different rated currents. The aim here is to keep the physical dimensions of a low-voltage power circuit breaker as low as possible.
Low-voltage power circuit breakers of the type mentioned may be in the form of permanently installed circuit breakers on the one hand or withdrawable circuit breakers on the other hand. In the case of withdrawable circuit breakers, the power circuit breaker is moved and locked in a withdrawable part rack which is provided for this purpose. This makes it possible to connect or isolate the power circuit breaker to or from the busbars more quickly and more easily than in the case of permanently installed circuit breakers. It is therefore desirable to be able to convert permanently installed circuit breakers to withdrawable circuit breakers with as little complexity in terms of materials and work as possible.